The present invention relates to flat antennas, and more particularly to structure for connecting a low-noise block down-converter (LNB) electrically to a feed network in flat antennas. Commonly assigned U.S. Pat. No. 5,125,109, which provides relevant background in this particular field, is incorporated herein by reference. Other relevant flat antenna applications and patents include U.S. Pat. Nos. 4,761,654, 4,929,159, and 5,005,019, which also are incorporated herein by reference; and application Ser. Nos. 07/648,459 and 08/126,438, also incorporated herein by reference.
U.S. Pat. No. 5,125,109 discloses an LNB mounted on a power summing/combining network layer in a flat antenna (where the flat antenna acts as a receiver; where the antenna acts as a transmitter, this layer would be a power dividing/distributing network layer.) A coaxial connection and a microstrip/waveguide transition are provided for connecting the LNB to the power summing/combining network layer. While this structure works well, it suffers from two drawbacks, i.e. a difficulty in pre-testing the LNB unit prior to insertion into the antenna, and the time and effort required in final insertion and connection of the unit.
Other work by the assignee in the field, leading to another copending, commonly assigned application Ser. No. 08/115,789, whose disclosure also is incorporated herein by reference, improves upon the techniques disclosed in U.S. Pat. No. 5,125,109 by providing a novel stripline-to-microstrip transition. In accordance with the invention of application Ser. No. 08/115,789, a low noise amplifier (LNA; part of an LNB) is positioned between the ground planes of the antenna so as to take advantage of the symmetry of the E-field in the stripline in providing the transition. However, the same deficiencies exist, relative to the integrity of the electrical connection, as in U.S. Pat. No. 5,125,109.